Same - can use the native Tidal app on other devices fine. Logged out and back in again on Roon (the Tidal/Roon login connection seems to work OK) and it never connects within the application, get the same red error box - tried on Android and Windows desktop
ok, so the combination that seemed to sort it is, remove Tidal account from Roon, restart ROCK, log into Tidal on a local browser, add Tidal back into Roon (whilst still signed in on a local browser).